file comression

Question

hai friends,

I want compress a PDF file of size 30.9MB to few 100KB, by using codes in C#.NET

FileStream sourceFileStream = File.OpenRead(@"D:\CMS\newsample.pdf");

FileStream destFileStream = File.Create(@"D:\ newsample_new.pdf");

GZipStream compressingStream = new GZipStream(destFileStream, CompressionMode.Compress);

byte[] bytes = new byte[2800];

int bytesRead;

while ((bytesRead = sourceFileStream.Read(bytes, 0, bytes.Length)) != 0)

{

compressingStream.Write(bytes, 0, bytesRead);

}

sourceFileStream.Close();

compressingStream.Close();

destFileStream.Close();

 I use this code to compress the file but the compressed file size is 30.1MB only. Please tell me what is the change that I want to do in these code to get the above size or if there is any other option to done this compress process, please tell me 

thanks in advance